| Abstract: | Interleukin‐10 (IL‐10) is a key anti‐inflammatory cytokine. We aimed to assess IL‐10 and IL‐10 receptor (IL‐10R) expression in the gut, and determine whether these patterns are altered in patients with ulcerative colitis (UC). Formalin‐fixed paraffin‐embedded rectal and transverse colon sections were collected from three groups of patients: (a) control subjects with normal colonoscopy and without history of inflammatory bowel disease; (b) UC patients with extensive colitis or pancolitis (E3/E4 phenotype); and (c) UC patients with limited distal disease (E1/E2 phenotype; n = 8‐10 subjects per group). Immunohistochemistry (IHC) was performed to assess expression patterns of IL‐10, IL‐10R1 and IL‐10R2, and was correlated with clinical, endoscopic and histologic severity indices among patients. A trend towards increased IL‐10 expression was noted in rectal biopsies of patients with active UC, compared with controls. Moreover, IL‐10 levels were significantly increased in transverse colon biopsies of patients with extensive/pancolitis, compared with control subjects and patients with limited distal disease. Rectal IL‐10R1 and IL‐10R2 levels were comparable between control subject and patients with active UC. However, transverse colon IL‐10R1 levels were significantly higher in patients with E3/E4 colitis, compared with controls. Finally, we found no correlation between clinical, endoscopic and histologic severity of inflammation among UC patients and IL‐10, IL‐10R1 or IL‐10R2 expression in rectal sections. Mucosal expression patterns of IL‐10 and IL‐10R, evaluated by IHC, were overall similar between control subjects and patients with active UC. Given IL‐10’s anti‐inflammatory properties, additional studies are required to determine whether signalling through the IL‐10R is altered among these patients. |
